The large-N limit of the chiral condensate from twisted reduced models
Claudio Bonanno, Pietro Butti, Margarita Garcı́a Pérez, Antonio González-Arroyo, Ken-Ichi Ishikawa, M. Okawa
Abstract
A bstract We compute the large- N limit of the QCD chiral condensate on the lattice using twisted reduced models, and performing controlled continuum and chiral extrapolations. We perform two different calculations: one consists in extracting the chiral condensate from the quark mass dependence of the pion mass, and the other consists in extracting the chiral condensate from the behaviour of the mode number of the Wilson-Dirac operator for small eigenvalues. We find consistency between the results of the two methods, giving a joint estimate of lim N →∞ Σ( N ) /N = [184(13) MeV] 3 ( $$ \overline{\textrm{MS}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>MS</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> , μ = 2 GeV, taking the square root of the string tension $$ \sqrt{\sigma } $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>σ</mml:mi> </mml:msqrt> </mml:math> = 440 MeV to set the scale), in remarkable agreement with the SU(3) 2-flavor FLAG result.